Grade 7 Chapter 2 Review
Name: _______________________
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
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1. Shrews eat insects and earthworms. The shrew is an example of a herbivore.
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2. Plants use energy from the Sun to turn water and carbon dioxide into food material.
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3. Within an ecosystem, energy is used over and over again.
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4. A parasitic worm that infects only foxes will have no effect on the population of lemmings.
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5. A relationship that benefits one organism and does not affect the other organism in a positive or
negative way is called parasitism.
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6. Spiders eat insects that eat plants. A spider is an example of a parasite.
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7. You see a raven eating a road-killed squirrel. That raven is behaving as a carnivore.
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8. A food web is a model that shows how energy is lost at each link in the food chain.
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9. Grass is eaten by mice that, in turn, are eaten by bears. In the related energy pyramid, almost all of
the energy produced by the grass ends up in the population of bears.
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____ 10. Chickens are omnivores because they eat both plants and animals.
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____ 11. Moose and hares are examples of carnivores because they only eat plants.
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____ 12. In a parasitic relationship, the organism that provides food for the other organism is the parasite.
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____ 13. In a mutualistic relationship, both organisms benefit.
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____ 14. When an earthworm is eaten by a mole, the earthworm is an example of a nutrient.
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Completion
Complete each statement.
15. Activities such as walking, writing, and playing baseball all require the use of
____________________.
16. The original source of energy in forest ecosystems is the ____________________.
17. A thousand green plants are needed to feed a hundred insects. Those hundred insects are needed to
feed one wren. This pattern of food consumption is called a(n) ________________________.
18. Plants trap energy from the Sun to make their own food. Thus, plants fill the role of
____________________ in food chains.
19. In their ecosystem, fish, lemmings, and polar bears fill the roles of ______________.
20. Parasitism, mutualism, and commensalism are _____________ relationships.
21. A chicken will eat plants, insects and worms. Such a consumer is called a(n) ____________.
22. The model shown below is a(n) _________________________.
23. Carbon and nitrogen are examples of ____________ that might be found in a backyard fish pond.
24. A flea biting a fox is an example of the type of symbiotic relationship which is called
_____________.
25. Bees are specialized to eat nectar from plants such as dandelions and goldenrod. The dandelions
and goldenrod are ________________.
26. When decomposers have finished consuming a dead earthworm, the earthworm has been changed
into ______________.
27. Bees depend upon flowering plants for food. Flowering plants depend upon bees for pollination.
Bees and flowering plants are involved in a relationship known as _______________.
28. The model shown below is a(n) ________________.
Matching
Match the term to the appropriate description. Each term is only used once.
a. producer
f. decomposers
b. consumer
g. fermentation
c. photosynthesis
h. herbivore
d. omnivore
i. nutrients
e. carnivore
j. energy
____ 29. animals that eat plants and animals
____ 30. the breakdown of sugar to produce alcohol and carbon dioxide
____ 31. the process by which plants make their own food
____ 32. organisms that break down plants and animal materials into nutrients
____ 33. animals that eat only plants
____ 34. what all organisms need to function and survive
____ 35. used to repair cells and tissue
____ 36. an organism that eats other organisms to obtain food
____ 37. an animal that eats other animals
____ 38. an organism that obtains its energy directly from the sun
Match the term in the table below to an appropriate example. Each term is only used once.
a. food chain
f. host
b. symbiosis
g. scavenger
c. commensalism
h. food web
d. nutrient cycle
i. mutualism
e. energy pyramid
j. parasite
____ 39. Carbon moves through the biotic and abiotic parts of the environment
____ 40. A bear in the act of feeding upon a road-killed fox
____ 41. A lobster with tiny worms living on its back
____ 42. A louse in the act of feeding upon a bird’s blood
____ 43. All of the plants, insects and birds that feed upon each other
____ 44. You, whenever you allow a mosquito to make a meal of you
____ 45. Moss growing upon the bark of a tree
____ 46. One million phytoplankton feeding ten snails
____ 47. A flower, a moth, and a bat
____ 48. Termites need decomposers and decomposers need termites to digest wood
Short Answer
49. What is photosynthesis? Choose one example, and write two or three sentences to describe the
process of photosynthesis. Explain what is used, what is produced, and where the process takes
place.
50. What is a decomposer? Choose one example, and write two or three sentences to describe the role
of a decomposer. Explain what they consume, what they produce, and at what level of the food
chain decomposers act.
51. Describe a food chain that includes you, one food that you regularly eat, and one level below that.
52. Draw a nutrient cycle that includes at least four different organisms. Identify the necessary biotic and
abiotic parts.
53. Look at the illustration showing carrion beetles at work. Are they scavengers or decomposers?
Explain your answer by describing the difference between scavengers and decomposers.
Essay
54. Examine the diagram below.
a) Explain what is represented by this model.
b) Explain how scavengers and decomposers fit into this model.
55. Describe a food chain that has either a coyote or a polar bear as the consumer.
56. A moose eats grass for energy. Only about 10% of the energy from the grass is stored in the moose’s
body. Explain what might have happened to the rest of the energy from the grass eaten. Be as
specific as possible.
57. A typical food chain consists of a producer, a primary consumer and a secondary consumer.
a) What does a producer do? Choose an example to illustrate.
b) What do the primary consumer and the secondary consumer do? Explain, using appropriate
examples.
c) Draw a food chain to connect the organisms you have described.
Grade 7 Chapter 2 Review
Answer Section
MODIFIED TRUE/FALSE
1. ANS: F
The shrew is an example of a carnivore. Insects and earthworms are animals; therefore the shrew is
a carnivore
2. ANS: T
3. ANS: F
Within an ecosystem, matter is used over and over again. Energy is transferred and lost as heat.
4. ANS: F
A parasite that infects only foxes will have an effect on the population of lemmings. It will limit the
population and activity of the foxes and the population of lemmings will likely increase as a result.
5. ANS: F
A relationship that benefits one organism and does not affect the other organism in a positive or
negative way is called commensalism.
6. ANS: F
A spider is an example of a consumer, specifically a secondary consumer.
7. ANS: F
That raven is behaving as a scavenger.
8. ANS: F
An energy pyramid is a model that shows how energy is lost at each link in the food chain.
9. ANS: F
In the related energy pyramid, very little of the energy produced by the grass ends up in the
population of bears. In an energy pyramid, thousands of plants supply a large amount of energy to
the food chain, but the bears would receive only a tiny amount of this energy.
10. ANS: T
11. ANS: F
Moose and hares are examples of herbivores because they only eat plants.
12. ANS: F
In a parasitic relationship, the organism that provides food for the other organism is the host.
13. ANS: T
14. ANS: F
If it is eaten by a predator, the worm is prey. Only if the worm was completely broken down into
molecules would it be considered nutrients.
COMPLETION
15. ANS: energy
16. ANS: Sun
17. ANS: energy pyramid
18. ANS: producers
19. ANS: consumers
20. ANS: symbiotic
21. ANS: omnivore
22. ANS: energy pyramid
23. ANS: nutrients
24. ANS: parasitism
25. ANS: producers
26. ANS: nutrients
27. ANS: mutualism
28. ANS: food web
MATCHING
29.
30.
31.
32.
33.
34.
35.
36.
37.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
D
G
C
F
H
J
I
B
E
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
D
G
B
J
H
F
C
E
A
I
SHORT ANSWER
49. ANS:
Photosynthesis is the process by which green plants make food. Sunlight is absorbed by the green
leaves of the spinach plant. The energy from the sun is then used to change carbon dioxide from the
air, and water from the soil, into food energy and oxygen.
50. ANS:
Decomposers are organisms that digest organic matter. Bacteria or mould secrete digestive
chemicals that break down dead matter outside their bodies. The material they digest could be
anything, dead or alive, but it tends to be mostly dead matter, such as decaying animal wastes. The
products of their digestion are small nutrient molecules. Decomposers are at work at all levels of
every food chain.
51. ANS:
Student answers may vary.
• Student eats chicken; chicken eats grain; grain is the primary producer.
• Student eats wild duck or fish; wild duck/fish eats small insects; insects eat plants; plants are the
primary producer.
52. ANS:
Student answers should include a predator, prey, food for the prey, and decomposers.
53. ANS:
The carrion beetles are scavengers. Scavengers work by eating the carcass. Decomposers break it
down into nutrients.
ESSAY
54. ANS:
a) This pyramid of energy is a model of an ecosystem. It represents the amount of energy available
at each level of a food chain. Producers have the most available energy in a food chain. They are the
most numerous and form the bottom layer. The number of organisms become fewer as the level of
consumers goes up toward the top of the pyramid because there is less energy available to organisms
at each link in a food chain. Only 10% of the energy from each level is passed to the next level in a
food chain.
b) All of the organisms in this diagram eventually die. When they die, the animals are all consumed
by scavengers. All of the organisms, including the grasses, are consumed by decomposers. Each
level of organisms in the energy pyramid has its own set of scavengers and decomposers. Each level
of scavengers can form the base of a new energy pyramid, since they, in turn, are eaten by other
organisms. The scavengers and decomposers, like other organisms, harvest about 10 percent of the
energy present in the level below them, and release the rest of the energy into the environment.
Decomposers turn each organism into simpler nutrients that are eventually used again by plants.
55. ANS:
Response will vary. Possible answers are:
• Vegetable to rabbit to coyote
• Phytoplankton to zooplankton to small fish to big fish to seal to polar bear
56. ANS:
The rest of the energy from the grass might have been used by the moose for
• chewing food
• moving around
• digesting the grass
• carrying out life functions, such as breathing
• eliminating waste material, which might also contain stored energy
57. ANS:
a) Producers are plants that turn the Sun's energy into stored food energy. Grass grows using energy
from the Sun, so it is an example of a producer. Other organisms may eat the plants to obtain food
energy for themselves.
b) Consumers eat the food made by the producers. A grasshopper eats grass, so it is a primary
consumer. A secondary consumer eats a primary consumer. A bird that eats grasshoppers, for
example, would be a secondary consumer.
c) Grass (Producer)  Grasshopper (Primary Consumer/Herbivore)  Bird (Secondary
Consumer/Primary Carnivore)